Process of purifying boiler feed-water.



PATEN'IYED NOV. 3, 1903.

I. V; HOLMES. BROGESS OF PURIPYING BOILER FEED WATER.

APPLICATION FILED OUT. 30, 1902.

N0 MODEL.

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No. 743,387. 7 g

UNITED STATES Patented November 3, 1:03.

PATENT OFFICE.

ISAAC V. HOLMES, OF CHICAGO, ILLINOIS.

PROCESS OF PURIFYING BOILER FEED-.WATER.

.sPEGIFIOATION forming part of Letters Patent No. 743,387, dated November 3, 1903.

Application filed October 30, 1902.

To aZl whom it may concern:

Beit known that I, ISAAC V. HOLMES, a citizen of the United States, residing in the city of Chicago, in the county of Cook and State oflllinois, have invented certain new and useful Improvements in Processes of Purification of Boiler Feed-Water and in Methods of Causing Forced Circulation of Boiler-Water, of which the following is a specification.

My invention relates to methods of steam generation, and it particularly relates to processes of purification of boiler feed-water and also to methods of causing forced circulation of water within a boiler.

By utilizing the combined process and method of my invention the objectionable features of the processes and methods now known to the art for the separation of scaling impurities from water and the objectionable features present in the now known methods of creating a circulation of water within a boiler are done away with, and water in such quantity as may be desired may be readily, economically, and eifectively purified and fed to a boiler and the water within the boiler be given a forced circulation;

Impurities are held in solution in cold water by reason of the gases and fixed air therein. When the water is sufficiently heated, the air and gases are freed therefrom and the impurities then become in suspension. These and the other impurities which were in suspension in the cold water will either sink therein or rise toward its surface, accordingly as they are of greater or of less specific gravity than the water. When this action takes place within a boiler, if the impurities are not removed therefrom before they can find lodgment on the walls thereof they will form mud or scale, or both, and according to their nature, thickness, and location within the boiler will impair its efficiency and shorten i its life. To maintain the efficiency and to preserve the life of a boiler, thereby rendering it possible to obtain the best results from the use thereof, it is essential that the water within the boiler shall be purged of all mud or scale forming impurities, that it shall have a positive forced circulation, and that the supply of water to and its circulation within the boiler shall be controllable.

In the drawing I have illustrated one form Serial No- 129,422. (No model.)

of device which may be employed to carry out the process and method of my invention.

Referring to said drawing, which is in part an elevation and in part a vertical sectional view, and in which like reference-letters, indicate the same or "corresponding parts, A is a boiler; B, a dish or skimmer; C, a pipe connection communicating at one of its ends with the water at or approximate to the surface W thereof within the boiler and at its other end with the receiving end of the combined mixer and eliminator Ii, hereinafter more fully described; M, a pipe connection communicating at one of its ends with the water-delivery end of said mixer and at its other end with the drum d of the centrifugal separator D, which separator is adapted, in manner hereinafter more fully described, to eliminate suspended impurities from water passing through it, whether said impurities be of greater or of less specific gravity than the water; at, a passage for the exit of purged water from the separator communicating at one end with the exit end of the drum (1 and at its other end with the worm-pump E; F, a pipe connection communicating at one of its ends with the exit endof the pump and at its'other end with the feed-water-receiving space G within the boiler; H, a feed-watersupply pump; h, a pipe connection communicating at one of its ends with the delivery end of the pump H and at its other end with a feed-water heater I; J, a pipe'connection communicating at one of its ends with the water-delivery end of the feedwater heater and at its other end with the mixer L; K, a pipe connection communicating at one of its ends with the steam space or dome of the boiler and at its other end with the pipe connection J and preferably projecting thereinto and constructed to 'forma steam-jet. The pipes C F J K may be respectively controlled by suitable valves.

(Z is an electric motor controlling the revoluble parts of the centrifugal deviceD; G, the feed-water-receiving space within a common type of boiler. a

The operation of this form of device for effecting my improved process is briefiy as follows: When the worm-pump E is revolved at a sufficient speed by the electric motor, it sucks the air from the separator D, the mixer L, and the pipe connections communicating therewith, whereupon the surface-water of the Water within the boiler A is drawn over the skimmer B, thence it enters and passes through the mixer L, thence it proceeds to the separator D, whence, rid of its contained impurities, it will pass through the passage (1 to the pump E, which will thereafter discharge it through the pipe connection F into the feed-water-receiving space G within the boiler, where it will mingle with the water therein. At the same I time this action is taking place waterfrom the feed-water heater I enters the mixer through the pipe J, while steam passes from the boiler through the pipe K to the pipe connection J. The mingling of the steam with the water from the feed-water heater or from any suitable source of supply will raise the temperature of said water to or approximately to the temperature of the water within the boiler and of the water which is being drawn from the boiler through the pipe 0. At or approximate to the point j this boiler-water and supply-water will mingle. As this water before it can reach the separatorD must pass through one or both of the foraminated concentric members Z Z, a substantially perfect commingling of the waters is thereby obtained. The action of heat upon the water will liberate the gases and air therefrom, and these gases may be permitted to escape through the petcock Z Hence when the water is delivered to the drum d its contained impurities are in suspension and are incapable of reuniting with the liberated air and gases, and so are prevented from returning to a state of solution. If no forced circulation be desired, the pipe connections 0 may be omitted. Again, if desired, the pipe connections K may also be omitted, in which lat-ter case the water enter ing the mixer through the pipe 0 will sufficiently raise the temperature of the water entering the mixer through the pipe J to free the air and gases contained therein. It will of course be understood that water entering the mixer through the pipe J will proceed through the separator and thence to the water-receiving space of the boiler, being acted upon by the mixer and centrifugal separator in the same manner as the water proceeding from the boiler through the pipe connection 0. The drawing off of the surface-water (together withits containedimpurities,ifany) and. the returning of it (purged) to the feedwater-receiving space within the boiler creates a positive forced circulation of the water within the boiler and a constant repurging of such of the boiler-water as shall not have been evaporated into steam. This forced circulation and the quantity of water repurged may be increased or diminished by increasing or diminishing the speed of the motor and of the pump E or by suitably adjusting one or more of the valves which control the passage of water through the various pipe connections.

In the drawing I have illustrated one form as a whole; (1, a drum; d, partitions radially disposed within the drum and secured to the outer wall and to the hub d thereof; d an annular member revoluble with the drum and secured to the partitions; d an outlet for impurities of greater specific gravity than is the water, communicating with the dischargepassage d d, an out-let for purged water, communicating at one of its ends with the discharge end of the drum and at its other end with the non-revoluble bowl-shaped chamber (1 which chamber communicates with the wormpump E; 0Z fixed wings within the chamber 61'; d d concentric outlet-passages for the discharge of impurities of less specific gravity than is the water; (1 an electric motor. The pump E, member 61 partitions d, and drum (1 are seen red one to another and to the motor 61 by which they are revolubly. controlled, and rotate upon ball-bearings d.

Assuming the revoluble parts referred to to be revolving at a sufficiently high rate of speed and water containing impurities of both greater and less specific gravity than it possesses to be entering the separator, the said heavier impurities will be centrifugally moved toward the wall of the drum, where they will settle and be discharged from the bottom of the drum through the outlet d and the discharge-passage 01 while the said lighter impurities will be centrifugally moved toward the center of the drum, whence they will onter the pipe 01 through the apertures d following which they may be discharged therefrom. The liquid thus freed from the heavier impurities upon the one side and the lighter impurities upon the other is rendered substantially pure between said points. Said purged water by virtue of its specific gravity, the pressure caused by water entering the drum, and the positive action of the pump E will pass through the annular outlet-passage (1 (formed by the hub and the inner wall of the annular member (1 into the fixed chamber d wherein its rotary motion will be arrested by the fixed wings d Thence it will enter the pump and be discharged therefrom through the pipe F to the water-receiving space G within the boiler. The rotary motion of the purified water being, as described, suddenly arrested by the fixed wings d upon its entering the chamber 01 foam or froth will thereby be created upon it, which froth and extraneous matters that may possibly not have been discharged through the outlets d (1 may be discharged through the pipe d, which communicates at one of its ends with said chamber.

ICC

, scribed, and claimed the herein-shown combined mixer and air and gas eliminator. Briefly describing said mixer and its operation, L indicates the mixer as a whole; ll, concentric foraminated tubes or pipes; Z

.grooves or corrugations formed in the wall of the casing surrounding said pipes, said corrugations preferably increasingin depth from the receiving end of the mixer (where their depth is substantially nothing) to a point approximate to the delivery end of the mixer; Z a groove preferably of equal or of greater depth than the greatest depth of the corrugations Z l, a petcock controlling the escape from the mixer of the liberated gases and air; F, a tubular member communicating atone end with the pipe Z, whichlatter is controlled by the valve Z and at its other end communicating with and preferably supporting the foraminated concentric tubes 1 l in substantially concentric position to the casing surrounding said tubes. When water sufficiently heated to bringinto suspension its contained impurities enters the mixer through the pipe J and tube land pipe C and tube Z, it will pass through the foraminations in said tube,- becoming thereby thoroughly mingled. As the water passes along through the mixer toward the delivery end thereof it will carry said air and gases toward said end, they being borne along in said grooves until they enter the pocket Z at which point they will congregate, their further forward movement being arrested by the wall of said pocket nearest the delivery end of the mixer. As frequently as desired said air and gases may be discharged from the mixer through the petcock Z. Were these gases and air not eliminated from the water, but allowed to reunite therewith, the matters in solution prior to the liberation of the gases and free air would again become in solution. The advantage, therefore, of eliminating said gases and air from the liquid and delivering the water to the centrifugal separator with its contained impurities held in suspension against all possibility of becoming again in solution is obvious.

The advantages of using purged water in boilers are too obvious to require particularization. The advantages of creating a forced circulation are many, among which the following may be stated: Steam can be gotten up in much quicker time than were the water within the boiler not given a forced circulation, and particles of extraneous matters of greater specific gravity than the water within the boiler are kept in constant movement toward the surface of said water, whence they may be drawn 0% into the separator and eliminated. Now, ifwe assume that five thousand pounds of water enter the boiler per hour from the pump H, to compensate for the amount of water evaporated per hour to obtain a sufficient steam-pressure to produce one-hundred-and-fifty-horse power, that the boiler when normally filled contains fifteen thousand pounds of water, and that the capacity of the worm-pump E is seven thousand five hundred pounds of water per hour, it will be seen that every hour two thousand five hundred pounds more water is drawn from the boiler and purged by the centrifugal separator than is admitted to the boiler through the pump H, in consequence of which the excess water is purged and repurged, while a forced circulation is given of two thousand five hundred pounds of water per hour.

Whereas I have shown and described a specific centrifugal device and specific form of device for eliminating from heated liquids gases and air freed from liquid by the action of heat, it will be understood that the process and method of my invention comprehends any filtering or purifying device which will extract suspended impurities from Water. It also will be understood that my process and method comprehends the employment of any suitable means to bring into suspension the impurities held in solution in liquid. It will further be understood that as many of these purging and eliminating devices may be employed as desired, that any form of pump may be employed to deliver the purged water to the boiler, and it will be also understood that any suitablemeans whatsoever may be employed which will carry my improved process and method into effect.

It is obvious that in the means shown in the drawing for carrying out my invention one or a plurality of objects may beaccomplished.

Having thus described the process and method of my invention and illustrated in the drawing one form of apparatus which may be employed to accomplish the objects of the invention, what I claim as new, and desire to secure by Letters Patent, is-

1. The improved process of purification of boiler feed-water, which consists in causing the impurities in solution in said water to become in suspension therein; then in extracting the gases and air freed from said water in bringing into suspension the said impurities; then in centrifugally eliminating from said water, through separate discharge-passages, the heavy and light impurities held in suspension therein; and, finally, in delivering the water, purged of its impurities, gases, and freed air, to any suitable receptacle, as the feed-water-receiving space within a boiler,

substantially as described. 2. The improved process of purification of boiler feed-water, which consists in heating said feed-water sufficiently to bring into suspension impurities in solution in said water when it was cold; then in extracting the gases and air freed from the water by the action of heat thereon; then in centrifugally eliminating from said water, through separate discharge-passages, the heavy and light impurities held in suspension in said water; and,

finally, in delivering said purged water to gally eliminating from said Waters through separate discharge-passages, the heavy and light impurities held in suspension therein; and, finally, in delivering said purged waters to the feed-water-receiving space Within a boiler, substantially as described.

4:. The improved process of purification of boiler feed-Water and method of causing a forced circulation of boiler-Water, which consists in simultaneously conveying water from a feed-water heater to a mixing-chamber, water from or approximately from the surface of the Water within a boiler to said mixing-chamber, and steam from any suitable source of supply, as the steam space or dome of said boiler to said mixer, or to a point approximate thereto, and in communication therewith; then in causing said waters and the water occasioned by the condensation of the steam to thoroughly coinmingle Within said mixer; then in discharging from said mixer the air and gases freed from said waters by the action of heat thereon; then in centrifugally eliminating from said waters the impurities held in suspension therein; and, finally, in delivering said purged Waters to the feed-water-receiving space within said boiler, substantially as described.

ISAAC V. HOLMES. Witnesses:

CHARLES S. HILL, LYSANDER HILL. 

